block: inline bdrv_unallocated_blocks_are_zero()

The function has only one user: bdrv_co_block_status(). Inline it to
simplify reviewing of the following patches, which will finally drop
unallocated_blocks_are_zero field too.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-3-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

1 files changed, 8 insertions, 3 deletions

diff --git a/block/io.c b/block/io.c
index df8f2a9..36d4d56 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2407,15 +2407,20 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs,
     if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) {
         ret |= BDRV_BLOCK_ALLOCATED;
     } else if (want_zero) {
-        if (bdrv_unallocated_blocks_are_zero(bs)) {
-            ret |= BDRV_BLOCK_ZERO;
-        } else if (bs->backing) {
+        if (bs->backing) {
             BlockDriverState *bs2 = bs->backing->bs;
             int64_t size2 = bdrv_getlength(bs2);
 
             if (size2 >= 0 && offset >= size2) {
                 ret |= BDRV_BLOCK_ZERO;
             }
+        } else {
+            BlockDriverInfo bdi;
+            int ret2 = bdrv_get_info(bs, &bdi);
+
+            if (ret2 == 0 && bdi.unallocated_blocks_are_zero) {
+                ret |= BDRV_BLOCK_ZERO;
+            }
         }
     }